Data center path switch with improved path interconnection architecture

ABSTRACT

A data center path switch architecture permits path switching of the signal path of incoming signals to one or more output paths in real time without the need for manual intervention, and without delays associated with current data center network switches. In this architecture, a switching core capable of switching signals directly from the ingress of the switching core to alternate destination ports in real time, either under software or hardware control.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application No.62/020,894, filed on Jul. 3, 2014, entitled “Data Center Path SwitchWith Improved Path Interconnection Architecture” which is incorporatedherein in its entirety by reference.

BACKGROUND

1. Field

The present disclosure relates generally to data center path switchestypically used in data centers of enterprise networks and serviceprovider networks, and more particularly to high density data centerpath switches having the capability of switching entire data paths withlow latency path interconnections between input ports and the outputports.

2. Description of the Related Art

Telecommunication switching has a long history, evolving from manualswitching to early automatic electro-mechanical switching systems, suchas step-by-step switching systems and crossbar switching systems, tomore recent electronic and optical switching systems.

Digital and optical switching systems allowed for substantial growth inthe size of electronic switching systems to meet the needs of everexpanding communication networks. The progression to the more commondigital and optical switching systems was spurred on a belief that newersemiconductor (e.g., VLSI) and optical devices met the need for highspeed data transmissions.

With the evolution of telecommunication switching has been the evolutionof computers and the information age. In order to manage the increase indata transmissions between computers, data centers came to be. Datacenters have their roots in the huge computer rooms built during theearly ages of the computing industry. Early computer systems werecomplex to operate and maintain, and required a special environment inwhich to operate. During the boom of the microcomputer industry in the1980s, computers started to be deployed everywhere and systems, such asdedicated computers or servers, were developed to meet the demandscreated by the need to have the increasing number of computerscommunicate. During the latter part of the 20^(th) century and earlypart of the 21^(st) century, data centers grew significantly to meet theneeds of the Internet Age. To maintain business continuity and growrevenue, companies needed fast Internet connectivity and nonstopoperations to establish a presence on the Internet.

Today, data centers are built within the enterprise network, a serviceprovider network, or a shared, colocation facility where the networks ofmany disparate owners reside. With the significant increase in businessand individual use of the Internet, and the significant need forbandwidth to transmit high volumes of data, especially video andgraphics, data centers are again under pressure to evolve to handle theboom in growth. However, data centers are typically very expensive tobuild, operate and maintain, and data center operators are searching forways to reduce costs while increasing data processing and transmissioncapabilities, while meeting all reliability requirements.

To meet the ever increasing demands, network architectures have evolvedover the years to address these pressures, with old methodologies andtechnologies giving way to newer and supposedly faster methodologies andtechnologies.

In order to meet the increased demands, data center networkarchitectures have changed. Sometimes the changes to the networkarchitecture require significant rerouting of network connections, andsometimes the network architecture needs to be dynamic, changingfrequently. And, all this has to be achieved at today's fast rates withlittle or no failures or delays in the transmission of data.

To address such pressures data center network switches have evolved withthe capability of switching data traffic on a packet-by-packet basis,which is known as packet switching. While packet switching can changethe physical route of individual packets through the network, there aresome network applications where the requirement is to switch all thedata traffic from one physical route to a second physical route throughthe network, which is known as port switching, or path switching.

As seen in FIG. 1, current data center data center network switcharchitectures have a number of ports 108 interconnected by a switchingcore. The data center network switch 10 in FIG. 1 has a number of ports108, switch logic 106, and a Central Processing Unit (CPU) 102. The datacenter network switch 10 may also have a management interface unit 104that enables the data center network switch 10 to communicate with amanagement control unit 100 that configures the settings within datacenter network switch 10.

Each port 108 connects to switch logic 106 via data path 118. Inoperation, switch logic 106 receives a data stream from a particularport 108 and transfers or switches the data stream to an outgoing port108 as defined by configuration settings from management control unit100.

FIG. 2 shows more details of the architecture of the switch logic 106.Port 108, also called a transceiver, has a receiver which receives adata stream from a remote end via external medium 126, and a transmitterwhich transmits a data stream to the remote end via external medium 126.Path 118, between port 108 and switch logic 106, is shown here separatedinto two paths: path 114 is the data flow direction from port 108 toswitch logic 106 which is referred to here as the receive direction,while path 112 is the data flow direction from switch logic 106 to port108, which is referred to here as the transmit direction.

The data center network switch 10 receives a Physical Layer data streamon an input port 108A, extracts packets (e.g., the data and headerinformation) from the data stream via switch logic 106, and thentransmits the packets (e.g., the data and header information) out aPhysical Layer data stream on output port 108B. More specifically, inthe data center network switch configuration of FIG. 2, port 108Areceives a Physical Layer data stream (or signal) from the externalmedium 126A, which may be a wireless, Cat 6, Cat 6a, optical fiber, orother physical connection, and converts the data stream (or signal) fromthe Physical Layer data stream (or signal) form into an electrical datasignal that can be used within the switch logic, separates the serialdata and recovered timing information from the Physical Layer datastream (or signal), and passes the serial data stream, via connection114A, into a Serial/Deserializer 120 (here SerDes 120A). The SerDes 120Aconverts the serial data stream into a parallel interface format forMedia Access Control (MAC) sub-layer 122A. The MAC sub-layer 122A is aninterface between a network's Data Link Layer's Logical Link Control(LLC) sub-layer and its Physical Layer, and provides the network's DataLink Layer functions, including frame delimiting and identification,error checking, MAC addressing, and other functions. Packets are parsedby the MAC layer 122A, where header fields are extracted and passed viainterface bus 110 to CPU 102, which interprets the header information.

The data center network switch management control unit 100 communicatesinformation, such as configuration information, alarm information,status information, to the management interface unit 104, via controlpath 116. Routing tables 128 contain information to direct incomingpackets on a particular port 108 to outgoing packets on a particularport 108. The Routing tables 128 may be determined by known discoveryprotocol software within data center network switch 10, or CPU 102 mayreceive configuration information from the management control unit 100to set up a particular routing table configuration. CPU 102 looks up theoutput destination route for a packet, and modifies the outgoing packetheader, if necessary.

Switch fabric 124 then transfers the packet to an outgoing queue inoutgoing MAC layer 122B. Outgoing MAC layer 122B formats the outgoingpacket for transmission, and performs other Data Link Layer functions,such as generating a frame check sequence for outgoing packets. Thecompleted packet is then fed to outgoing SerDes 120B, which converts theparallel data stream into a serial data stream. The serial data streamis then fed to the outgoing port 108B, which converts the data streaminto a physical layer signal, adds physical layer timing, and transmitsthe physical layer signal out port 108B to external medium 126B.

Within current data center network switches 10, the number of steps totransfer an incoming physical layer signal from an incoming port 108 toan outgoing port 108 adds transmission delays and necessitatesmodifications to the outgoing packet. The current state of packetswitches has latency issues of about and in excess of 500 nsec perpacket, which is insufficient for today's data centers.

Further, a single data center network switch core can support only arelatively small number of ports. For a very large number of ports, datacenter network switch cores have to be configured in hierarchical ormesh configurations, which adds complexity to the network, decreasesreliability, and further increases latency.

Turning to path switching, in today's data centers, network applicationsmay employ; 1) an electrical-electrical-electrical path switch, 2) anelectrical-optical-electrical path switch, 3) anoptical-electrical-optical path switch, and/or 4) anoptical-optical-optical path switch.

Various switching techniques have been used to implement such pathswitching methodologies. Examples include crosspoint switching, spaceswitching, time slot switching, and wavelength switching to interconnectpaths from an incoming port to outgoing port. However, today's demandfor higher port counts in data center path switches restricts the abovepath switching techniques that may be employed to achieve high density,high speed path switching. Factors associated with such path switchingtechniques, such as high cost, low manufacturing yield, low reliability,high data latency, signal loss, power consumption, heat dissipation, andreal estate, have heretofore prevented the expansion of path switchingin today's high speed, high density data center data center pathswitches.

Currently available optical crosspoint switching technologies includeelectronic crosspoint switches, waveguides, beam steering,Micro-Electro-Mechanical Systems (MEMS), tunable filters, liquid crystalswitching, and thermo-optical polymers solutions.

However, MEMS for example, has low reliability due to moving parts(e.g., mirrors), and requires corrective circuitry to ensure accuratebeam alignment to correct for mirror misalignment. Another problem withMEMS is that as the number of ports being switched increases, the numberof mirrors must significantly increase, further increasing the lowreliability, mirror misalignment and path set up latency concerns.Increasing the number of mirrors also leads to more distance between theports and the mirrors, which creates an issue known as beam divergence,where each individual beam widens as it passes from mirror to mirrorresulting in signal loss along the path.

Physical sizes of MEMS hardware is also a problem and there are costissue with current MEMS applications. For example, to create 320×320port solutions in a MEMS application would require a physical size of 7data center Rack Units (RU) in a data center cabinet or rack.

Beam steering has similar issues where as the number of ports tointerconnect rises, the angular range increases and alignment anddistortion effects exceed the capabilities of transmitting reliablesignals.

With waveguide crosspoint switching, methods of path interconnectionsusing ink-jet or thermo capillary techniques to pass or reflect anoptical signal along the waveguide. However, using ink-jet or thermocapillary techniques to pass or reflect an optical signal along awaveguide typically generates significant heat, which creates heatdissipation and reliability issues.

Further, the different optical crosspoint switching techniques notedabove are not capable of scaling in size to support large productionapplications required in today's data center networks. With most ofthese crosspoint path switching techniques, complexity and costs riseexponentially as the number of ports increases making it very expensiveto meet the demands on today's data centers.

SUMMARY

The present application relates to a data center path switch thatimplements a path interconnection architecture to simplify current datacenter path switching structures. Preferably, the data center pathswitch according to the present application utilizes a pathinterconnection architecture that enables the switching of data streamson a channel of an ingress side of the path interconnection architectureto any one of the channels on an egress side of the path interconnectionarchitecture, or to enable the switching of data streams on a channel ofan ingress side of the path interconnection architecture to multiplechannels on an egress side of the path interconnection architecture.

The data center path switch according to the present applicationincreases the density within the path interconnection unit and dependingupon the intended embodiment, can provide a blocking or a non-blockinginterconnect solution while simplifying the control and pathinterconnections when switching ports.

The data center path switch according to the present application is alsocapable of switching optical and electrical signals from one externalmedium interface port to another similar medium interface port with noloss in performance across the path interconnection architecture. Thedata center path switch according to the present application is alsocapable of switching optical signals from optical medium interface portsto electrical medium interface ports with no loss in performance acrossthe path interconnection architecture. The data center path switchaccording to the present application is also capable of switchingelectrical signals from electrical medium interface ports to opticalmedium interface ports with no loss in performance across the pathinterconnection architecture. The data center path switch according tothe present application is also capable of switching optical signals ofone wavelength from optical medium interface ports to optical mediuminterface ports with a different optical wavelength with no loss inperformance across the path interconnection architecture.

The data center path switch according to the present applicationpreferably provides optical or electrical signal regeneration such thatthere is no signal quality loss while achieving low latency along thepath interconnections, as compared to current data center path switcharchitectures.

The data center path switch according to the present application mayprovide diagnostic and port status information to management layerfunctions for statistic information and for troubleshooting PhysicalLayer path connection issues.

Preferably, the path interconnection architecture used in the datacenter path switch according to the present application is capable ofscaling to several thousand ports with equivalent reliability andperformance and can be designed as a modular architecture.

In an alternate embodiment, the path interconnection architecture in thedata center path switch according to the present application permits theselective establishment of test monitor taps and multicast or broadcastconnections with no power level signal loss or latency in the outgoingside of the path interconnection architecture.

Preferably, the data center path switch according to the presentapplication can provide end to end path identification using, forexample, managed connectivity interfaces capable of identifying each ofthe cables connected to the data center path switch.

An example of an embodiment of the data center path switch according tothe present application includes a set of ports, a path interconnectionunit, and a control unit. Each port within the set of ports isconfigured to receive data streams from an external medium, and totransmit data streams to an external medium. The path interconnectionunit has an ingress side with a set of paths equal to the number ofingress ports in the set of ports, and an egress side with a set ofpaths equal to the number of paths on the ingress side. The pathinterconnection also includes an electrical based switching fabric thatis configured to switch data streams on any one ingress side path to anyone egress side path or multiple egress side paths. The latency of datastreams switched from a receiving port to a transmitting port is lessthan 500 nsec. The control unit is connected to the path interconnectionunit and is configured to control the switching fabric to switch datastreams from a path on the ingress side to one or more paths on theegress side.

Another example of an embodiment of the data center path switchaccording to the present application includes a set of ports in a one RUconfiguration having a capacity that is scalable from 16 ingress portsand 16 egress ports to at least 128 ingress ports and 128 egress ports.Each port within the set of ports is configured to receive data streamsfrom an external medium, and to transmit data streams to an externalmedium. A path interconnection unit is also provided. The pathinterconnection unit has an ingress side with a set of paths equal tothe number of ingress ports in the set of ports, and an egress side witha set of paths equal to the number of paths on the ingress side, and anelectrical based switching fabric that is configured to switch datastreams on any one ingress side path to any one or multiple egress sidepaths. A control unit is connected to the path interconnection unit andis configured to control the switching fabric to switch data streamsfrom a path on the ingress side to a path on the egress side.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of a data center network switch architecturewithin the prior art;

FIG. 2 is a block diagram of the data center network switch architectureof FIG. 1, detailing the switch logic;

FIG. 3 is a block diagram of an exemplary embodiment of a data centerpath switch according to the present application, illustrating a generalpath interconnection unit with ingress and egress sides;

FIG. 4 is a block diagram of an exemplary embodiment of a data centerpath switch according to the present application, illustrating amultistage non-blocking path interconnection unit with ingress andegress sides;

FIG. 5 is a block diagram of an exemplary embodiment of a data centerpath switch according to the present application, illustrating amultistage non-blocking path interconnection unit with ingress andegress sides and a port with a WDM transceiver configuration;

FIG. 6 is a block diagram of another exemplary embodiment of a datacenter path switch according to the present application, implementing amulticast application;

FIG. 7 is a block diagram of an exemplary embodiment of a data centerpath switch according to the present application implementing atest/monitor application;

FIG. 8 is a block diagram of an exemplary embodiment of a data centerpath switch according to the present application implementing atest/monitor application in a network configuration;

FIG. 9 is a block diagram of an exemplary embodiment of a data centerpath switch according to the present application implementingintelligent identification of cables; and

FIG. 10 is a block diagram of an exemplary embodiment of a data centerpath switch according to the present application detailing the internalfunctional logic blocks.

DETAILED DESCRIPTION

Referring now to FIG. 3, an exemplary architecture of the path switch300 according to the present application is provided. In thisembodiment, the path switch 300 includes a set of ports 308, pathinterconnection unit 306, management interface unit 304 and CPU 302. Thenumber of ports 308 and the bandwidth per port of the set of ports 308is generally set by the capability of the path interconnection unit 306.Preferably, the ports are transceiver ports capable of receivingPhysical Layer signals from various mediums, converting the signals intoa form that can be routed by the path interconnection unit 306, andconverting signals from the form routed by the path interconnection unit306 to a form for transmission as a Physical Layer signal through a port308 onto an external medium capable of handling such Physical Layersignal. The configuration of the data center path switch is such thatthe latency between an input port and an output port is less than 500nsec, and preferably less than 10 nsec at about 5 nsec.

The path interconnection unit 306 is preferably configured such that itcan transfer data streams from one channel of an ingress side 306A ofthe path interconnection unit 306 onto to any one channel on an egressside 306B of the path interconnection unit 306. The path interconnectionunit may be an electronic matrix type switch, such as a crossbar orcrosspoint switch. The electronic matrix type switch may use multiplexorarrays, selective transistor enabling, or other implementation toselectively choose one input to be interconnected to a single output, orto multiple outputs. A suitable matrix type switch is described in “A10-Gb/s High-Isolation, 16×16 Crosspoint Switch Implemented WithAlGaAs/GaAs HBT's”, IEEE Journal of Solid State Circuits, Vol. 35, No.4, April 2000, which is incorporated herein by reference. The capabilityexists within matrix type switches to enable multiple multiplexor arraysor transistors or other mechanism to connect one input port to one ormore output ports. Other embodiments of matrix type switches may alsoprovide the capability of connecting multiple inputs to a single outputport simultaneously.

Electronic matrix type switches can easily be designed to support alarger number of ingress and egress ports by cascading crosspoint groupsinto multistage path interconnection unit 306 as shown in FIG. 4. Asnoted above, preferably the data center path switch has a port set thatis capable of scaling from, for example, 16×16 ports to 128×128 ports ina single rack unit. As another example, using an electronic matrix typeswitch in the path interconnection unit allows a configuration that canscale to support ports sets of 320×320 ports or more in a single rackunit.

Control of the flow of a data stream through the path interconnectionunit 306 is through the management interface unit 304 and the CPU 302.In the embodiment of FIG. 3, received Physical Layer signals areconverted by ports 308 into electrical signals that are transferred topath interconnection unit 306.

The data center path switch 300 in the embodiment of FIG. 3, isconfigured by the management control unit 100 which communicatesinformation, such as configuration information to CPU 302 via managementinterface unit 304 and control path 316. The configuration informationis used by CPU 302 to configure the ports 308 and the pathinterconnection unit 306. An incoming path 314 on a particular port 308may be assigned an outgoing path 312 to a particular port 308, which maybe the same port or another port 308. In this way, the network topologycan be reconfigured from one physical destination to another destinationby the management control unit 100 modifying the configuration settingsin path interconnection unit 306. As a result, network traffic can beredirected by software control without the need for manual humanphysical reconfiguration of the ports.

The data center path switch architecture of the present disclosurepermits the hardware for ports 308 to be made configurable by softwarereconfiguration under control of the CPU 302. The data center pathswitch architecture can also be configured with automatic failovermechanisms for redundancy applications, such that in the event of afailed input or output port or loss of signal on a given port, the pathinterconnection port can be switched to utilize a different input portand or output port.

The data center path switch architecture of the present disclosurepermits different ports 308 to be implemented to support differentmedium interfaces. For example, by designing the port interfaces 308according to medium type the data center path switch topology can bereconfigured by medium type, such that path interconnection unit 306 cannot only support each medium type, but also can provide aninterconnection method from one medium type to another medium type. Toillustrate, port 308A can be configured for a Cat 6 copper medium whileport 308B can be configured for a fiber cable medium with both portsinterconnected through path interconnection unit 306.

The connectors for ports 308 can include copper interfaces, such as Cat5, Cat 6, Cat 7, and other RJ45 implementation variations, fiber channelinterfaces, optical interfaces, such as SC, ST, FC, LC, MPO (sometimescalled MTP), MXC, and other fiber type connections. The ports 308 canalso consist of Small Form Factor (SFF) or other type of modular cagescapable of accepting plug-in type transceivers, such as SFP, SFP+, QSFP,CFP, and other modular transceiver modules. In one embodiment, the datacenter path switch architecture of the present disclosure may consistentirely of electrical connectors. In another embodiment, the datacenter path switch architecture of the present disclosure may consist ofa mixture of optical and electronic connectors.

In another embodiment shown in FIG. 5, port 308G may consist ofWavelength Division Multiplexor (WDM) interfaces, such as CoarseWavelength Division Multiplexor (CWDM), Dense Wavelength DivisionMultiplexor (DWDM), or other WDM capabilities, such as silicon photonicsinterfaces where multiple wavelengths may be received over a singleinput fiber. In this embodiment, the WDM transceiver interface wouldthen split up the individual wavelengths and convert the signal fromeach optical wavelength to individual electrical paths 314A, 314B, 314C.The individual electrical paths 314A, 314B, 314C can then be switched asdescribed previously within the path interconnection unit 306 to theselected output paths 312 as programmed into path interconnection unit306 by CPU 302. Outputs from path interconnection unit 306 connectindividual electrical paths 312A, 312B, 312C into the transmit side ofWDM transceiver port 308G to be converted into different wavelengths tobe transmitted out the WDM transceiver port 308G. One embodiment mayhave the path interconnection unit 306 configuration set to have all theWDM wavelengths from one input WDM transceiver port 308G connect viaelectrical paths 314A, 314B, 314C to a separate WDM transceiver port308G (not shown) via electrical paths 312A, 312B, 312C. Anotherembodiment is to use path interconnection unit 306 to cross connect thedifferent WDM channel input wavelengths from input WDM transceiver port308G to different output wavelengths in the same outgoing WDMtransceiver port 308G, e.g., connection paths 314A, 314B, 314C to paths312C, 312B, 312A. Another embodiment is to connect the WDM transceiverport 308G to individual electrical paths 314A, 314B, 314C to separateindividual ports 308B, 308C, 308D, 308E, or 308F, which may includeinterfaces, such as Cat 5, Cat 6, Cat 7, or other copper RJ45implementation variations, fiber optical interfaces including SC, ST,FC, LC, MPO, MXC type connections, or to SFF or other type of modularcages intended to accept plug in transceivers such as SFP, SFP+, QSFP,CFP, and other modular transceiver modules.

In the data center path switch architecture of the present disclosure,since the intention is to create a very dense solution and smallenclosure to reduce the data center real estate, the preferredembodiment application uses MPO or MXC type fiber connectors.Furthermore, to reduce the physical data center path switch size, thedata center path switch preferably uses multiport fiber optictransceiver port chips, such as the Board-mount Optical Assemblytransceivers, manufactured by Finisar Corporation.

The CPU 302 configures the ports 308 based on configuration informationfrom management control unit 100. The CPU 302 also monitors each port'sstatus and the status of the path from each port 308, and reportsdiagnostic and status information to the external management controlunit 100 for statistics and troubleshooting.

Electrical and optical cable distances are range bound as signal qualitymay degrade as the signal distance increases from a transmitter, frominsertion loss from connectors or cables, or from other impairments. Thedata center path switch architecture of the present disclosureterminates the incoming signal at ingress port 308 and then regeneratesthe output signal at egress port 308, which effectively resolves signaldegradation. This solution can also be used in applications, such asextending the permissible distance of a path for example.

The scale of the configuration is dependent upon the size of the pathinterconnection, e.g., the crosspoint, implemented. The data center pathswitch architecture of the present disclosure is scalable byimplementing path interconnection unit designs, either blocking ornon-blocking, matrix type switches (e.g., crosspoint switches) and whichmay include single stage solutions or multistage solutions. Examples ofsuch solutions include Banyan Networks, Batcher Networks, Batcher-BanyanNetworks, Clos Networks, or other interconnection methodologies. Oneimplementation configuration for the data center path switcharchitecture of the present disclosure can support in excess of 320×320ports in a single RU with less than 10 nsec latency.

The data center path switch architecture of the present disclosure isintended to support path signal switching which switches the entirephysical signal and does not interpret the data. As a result, thearchitecture can support multiple software protocols simultaneouslyacross the path interconnection unit 306.

The data center path switch architecture of the present disclosure alsopermits the capability of grouping multiple paths together to provideparallel interface connections, such as 40 Gbps and 100 Gbps. In thisconfiguration, parallel streams of 10 Gbps from an ingress 40 Gbps or100 Gbps port 308 are bonded together within path interconnection unit306 by using grouped interconnection paths which have low intra-pathskew. In this configuration, parallel streams of 10 Gbps from an ingress40 Gbps or 100 Gbps port 308 are bonded together within pathinterconnection unit 306 by configuring paths with similar routesthrough the circuitry comprising of paths 314, then through pathinterconnection unit 306 and then through paths 312 to create groupedinterconnection paths which have low intra-path skew.

An alternate 100 Gbps implementation utilizes four lanes of 25 Gbps. Fordata rate translation with a 10 Gbps cross connect switch, a “Gearbox”PHY that multiplexes and de-multiplexes the four 25 Gbps channelsto/from ten 10 Gbps channels can be used to convert a 100 Gbps interfaceutilizing 4 lanes of 25 Gbps channels into 10 lanes into/from the 10Gbps lanes of the crosspoint switch. An example of one implementationusing the Gearbox PHY is a BCM84790 from Broadcom Corp.

In an alternate configuration, parallel streams of 25 Gbps from aningress 100 Gbps port 308 are bonded together within pathinterconnection unit 306 capable of supporting 25 Gbps or highertransmission paths by configuring paths with similar routes through thecircuitry comprising of paths 314, then through path interconnectionunit 306 and then through paths 312 to create grouped interconnectionpaths which have low intra-path skew.

The data center path switch architecture of the present disclosure alsopermits the capability of providing broadcast from one port to all portssimultaneously, or providing multicast from one port to multiple portssimultaneously. FIG. 6 shows one example of a multicast implementationwhere port 308A is configure to receive traffic into the pathinterconnection unit and multicast the signal out of ports 308B, 308C,308E, and 308F. Management control unit 100 communicates to managementinterface unit 304 the configuration settings for the broadcast ormulticast implementation. CPU 302 then, via control bus 310, configuresthe path interconnection unit 306 in order to set up the path or channelconnections necessary for the broadcast or multicast configuration. Inthe embodiment of FIG. 6, a data stream on path 314 from port 308A isconnected by path interconnection unit 306 to ports 308B, 308C, 308E,and 308F via paths 318, which are identical paths in parallel from inputpath 314. The input paths 314 from ports 308B, 308C, 308E, and 308F maybe connected (not shown) to other ports 308, or may not be connectedanywhere within the path interconnection unit 306 (not shown).

Each fiber connector may have one or more associated Light EmittingDiodes (LEDs) used for status and control information. Each LED may be asingle color or multicolor LED as determined for the productimplementation. Each LED may have a blink rate and color used toidentify specific states for the port. The LEDs can be illuminated byCPU 302 to indicate information and may include port status for a singleactive port or multiple ports for each connector. The LEDs can also beused during installation or Moves-Adds-and-Changes to indicate to datacenter personnel which connector port is to be serviced. CPU 302 mayalso indicate port status information by a Liquid Crystal Display (LCD)located near the panel connectors.

The data center path switch architecture of the present disclosure alsopermits the implementation of configuring port mirroring ports in orderto connect primary path data streams to test/monitor ports by allocatingmore than one network paths, as shown in FIG. 7 in the architecturesimilar to the multicast architecture of FIG. 6, which will steer thepath from an incoming port to an outgoing network port plus also to aport designated to a test/monitor platform. In the embodiment of FIG. 7,path 314 from port 308A is fed into the path interconnection unit 306and under configuration from CPU 302 is replicated within pathinterconnection unit 306 to produce two copies of path 314 designated asoutput paths 318. One copy of path 318 is fed to port 308B to theintended destination medium, while the other path 318 is fed to port308C intended for a test/monitor platform external to the data centerpath switch 300, as seen in FIG. 8. Additionally, the receive path 314from port 308B through path interconnection unit 306 to egress path 312to outgoing port 308A may also be port mirrored within pathinterconnection unit 306 and the duplicated signal may be copied to adifferent port 308 for forwarding to the test/monitor platform as well.In this embodiment, the data center path switch architecture of thepresent disclosure provides via the management control unit 100, anetwork operator selectable path to the test/monitor platform, adds zerolatency to the original communication path for test/monitor ports,eliminates the requirement of physically moving the connections, andeliminates any down time associated with setting up and removing thetest/monitor connections.

Typical Network Taps are hardware devices which split an electrical oroptical data stream into two segments—one path being connected to theoriginal intended destination and the other path to the Test/Monitorsystem. The splitting of the optical signal using Network Taps reducesthe signal power which in turn reduces the maximum distance the signalcan reach before errors start occurring. Using the data center pathswitch architecture of the present disclosure eliminates the splittingand in fact increases the distance a signal can reach because the signalis regenerated in the data center path switch 300 by transceiver ports308.

Preferably, the data center path switch architecture of the presentdisclosure may have multiple port mirroring ports for testing and ormonitoring of any of the input signal paths to the data center pathswitch.

Referring to FIG. 9, the architecture of the present disclosure alsopermits the implementation of the capability to interpret cableinformation from cables connected to the data center path switch 400, byobtaining intelligent information from within the cables. In thisembodiment, the CPU 302 can then report the physical cable informationto the management control unit 100. In addition to interfacing tostandard cables 212, and intelligence equipped cables 412, adapter 402has the capability, via interface 404, to detect the presence of a cableconnector 214 or 414 inserted into intelligent adapter 402, and in thecase of intelligence equipped cable connector 414, read specific cableinformation by reading the information in cable media 416. To ascertaincable information, the data center path switch 400 may be designed withninth wire technologies interfaces, RFID tagging technology interfaces,connection point ID (CPID) technology interfaces, or other cable managedintelligence technologies. In another embodiment, the data center pathswitch 400 may be designed with one or more of these differenttechnology interfaces in order to provide the capabilities of supportingmore than one particular managed intelligent technology.

Each data center path switch 400 equipped with intelligent cableinterfaces has the capability to determine the cable presence and/orcable information available to the interface depending upon theinformation provided from the intelligent cable.

The cable information read from media interface adapter 402 via mediainterface bus 418 by media reading interface logic 406 and provided toCPU 302 may consist for each cable connection of the cable type, cableconfiguration, cable length, cable part number, cable serial number, andother information available to be read by media reading interface logic406. This information is collected by media reading interface logic 406and passed to the CPU 302 via control bus 310. The CPU 302 then reportsthe information to management control unit 100. Management control unit100 can use this information along with information received from otherData center Path Switches 400 to map out the end to end connection pathsof each cable connected in the Data Center.

FIG. 10 shows an embodiment of the internal functional blocks of thedata center path switch. In this embodiment, the CPU 302 configures thepath interconnection unit 306 as well as the ports 308 and monitors theports to ensure the port interfaces are functioning within expectednormal operating parameters. Configuration of the path interconnectionunit 306 and the ports 308 may be a one-time function upon power onsequence, or the configuration may be changed dynamically based uponexternal data center requirements depending on the implementedapplication.

Continuing to refer to FIG. 10, an Ethernet interface 502 is incommunication with CPU 302 and is employed to exchange informationbetween the CPU and the external management control unit 100. In oneembodiment, the CPU may have configuration information pre-programmed inmemory 516, while other embodiments may require programming based uponthe actual implementation within a customer application. Memory 516 isalso used for program software code and to retain port status and alarminformation, front panel indication status power supply status, ManagedConnectivity status and alarm information, Ethernet port configurationsettings, Management Control interface information, and other relatedconfiguration and status information.

The Port alarm and status block monitors each port for change in statusof a port 308 or a connection to that port 308 in order to report portstatus to the CPU 302 and if required to the Management Control Unit100. Depending upon the configuration settings for a given embodiment,the CPU 302 may merely report the port status change or may switch out afailed physical port 308 and may connect an alternate port 308 throughPath Interconnection Unit 306 in redundancy applications in order toprovide an end-to-end connection for the path.

The Managed Connectivity Interface 514 controls media reading Interfacelogic 406 to detect the insertion, presence, and removal of a connector214 or 414 within adapter 402 and then by reading media interface 416 ifpresent to determine the cable and connector information from theinserted cable. This information is then reported to CPU 302 which inturn passes the information to Management Control Unit 100, Using thisinformation, a software controlled touchless reconfigurable networkwhere the management control unit 100 can modify the configuration ofpath interconnection unit 306 to create alternate routes within thenetwork. In one configuration, the output ports 308 can provideadditional parallel paths to a single destination node within thenetwork to provide redundant connections which can be activated by theCPU 302, without the need for manual intervention, upon detection of afailure in the primary outgoing path connection to the destination node.In another configuration, once the physical connections have been madebetween the nodes or endpoints within the network, the managementcontrol unit 100 can reconfigure the network topology without requiringpersonnel to manually reconnect the interconnections. For example,alternate network reconfiguration implementations can be achieved byswitching an input port 308 to an alternate port 308, which is connectedto a different destination node or endpoint in the network. To furtherillustrate this example, an initial network configuration may have inputfrom port 308B connected to a destination node “A” via outgoing port308C. A network operator or the management control unit may decide toreconfigure the connections from port 308B to destination node “B” byreconfiguring path interconnection unit 306 to connect port 308B to port308F. By configuring the network with alternate paths to different nodesor endpoint destinations, the path interconnection unit 306 can switchthe route from a source to a new destination, thereby changing thenetwork topology.

The data center path switch may also have peripheral functions, such aspower supply and thermal monitoring unit 504, as well as front paneldisplay 506 employed to manage hardware such as LEDs, LCDs, and/or otherdisplay methods, and may also have input mechanisms such as pushbuttonsto provide input to the CPU. Additional logic blocks may also be addedfor various purposes. One example would be dedicated fail over hardwarefrom one port 308 to one or more alternate ports 308 in case of failureof the primary port 308 for example.

As will be appreciated by one skilled in the art, aspects of the presentdisclosure may be embodied as a system, method or computer programproduct. Accordingly, aspects of the present disclosure may take theform of an entirely hardware embodiment, an entirely software embodiment(including firmware, resident software, micro-code, etc.) or anembodiment combining software and hardware aspects that may allgenerally be referred to herein as a “module” or “system.”

Computer program code for carrying out operations for aspects of thepresent invention may be written in any combination of one or moreprogramming languages, including an object oriented programming languagesuch as Java, Smalltalk, C++ or the like and conventional proceduralprogramming languages, such as the “C” programming language or similarprogramming languages.

With certain illustrated embodiments described above, it is to beappreciated that various non-limiting embodiments described herein maybe used separately, combined or selectively combined for specificapplications. Further, some of the various features of the abovenon-limiting embodiments may be used without the corresponding use ofother described features. The foregoing description should therefore beconsidered as merely illustrative of the principles, teachings andexemplary embodiments of this invention, and not in limitation thereof.

It is also to be understood that the above-described arrangements areonly illustrative of the application of the principles of theillustrated embodiments. Numerous modifications and alternativearrangements may be devised by those skilled in the art withoutdeparting from the scope of the illustrated embodiments, and theappended claims are intended to cover such modifications andarrangements.

What is claimed is:
 1. A data center path switch, comprising: a set ofports, wherein each port within the set of ports is configured toreceive data streams from an external medium, and to transmit datastreams to an external medium; a path interconnection unit having aningress side with a set of paths equal to the number of ingress ports inthe set of ports, and an egress side with a set of paths equal to thenumber of paths on the ingress side, and an electrical based switchingfabric that is configured to switch data streams on any one ingress sidepath to any one egress side path; and a control unit connected to thepath interconnection unit configured to control the switching fabric toswitch data streams from a path on the ingress side to a path on theegress side; and wherein the latency of data streams switched from areceiving port to a transmitting port is less than 500 nsec.
 2. The datacenter path switch according to claim 1, wherein the latency of datastreams switched from a receiving port to a transmitting port is lessthan 10 nsec.
 3. The data center path switch according to claim 1,wherein the set of ports and path interconnection unit are configured asa non-blocking path switch.
 4. The data center path switch according toclaim 1, wherein the path interconnection unit comprises a matrix ofswitches of sufficient size such that a data stream on the ingress sidecan be switched to any one of the paths on the egress side.
 5. The datacenter path switch according to claim 1, wherein the switching fabric isconfigured to switch data streams on any one ingress side path to morethan one egress side path.
 6. The data center path switch according toclaim 1, wherein a data stream from a receiving port comprised of onemedium type is converted within the path switch such that such datastream is transmitted by a transmitting port of a different medium type.7. The data center path switch according to claim 1, wherein a datastream from a receiving port comprised of an electrical medium type isconverted within the path switch such that such data stream istransmitted by a transmitting port of an optical medium type.
 8. Thedata center path switch according to claim 1, wherein a received datastream is at a first data rate is converted into a second data rate atthe path interconnection unit.
 9. The data center path switch accordingto claim 1, wherein each port in the set of ports includes a connectorcapable of connecting to the external medium.
 10. The data center pathswitch according to claim 9, wherein at least one of the port connectorscomprises a copper connector.
 11. The data center path switch accordingto claim 9, wherein at least one of the port connectors comprises one ofa simplex or duplex fiber connector.
 12. The data center path switchaccording to claim 9, wherein at least one of the port connectorscomprises a high density fiber connector.
 13. The data center pathswitch according to claim 9, wherein at least one of the port connectorshas one or more associated LEDs used for status and control information.14. The data center path switch according to claim 1, wherein each portin the set of ports includes a transceiver.
 15. The data center pathswitch according to claim 14, wherein the transceiver comprises apluggable transceiver in an SFF modular cage.
 16. The data center pathswitch according to claim 14, wherein the transceiver comprises a WDMtransceiver.
 17. The data center path switch according to claim 1,wherein one or more of the ports in the set of ports comprise managedconnectivity ports capable of reading a physical location identificationfrom a managed connectivity port from an external medium connected tothe one or more ports in the set of ports.
 18. A data center pathswitch, comprising: a set of ports in a one RU configuration having acapacity that is scalable from 16 ingress ports and 16 egress ports toat least 128 ingress ports and 128 egress ports, wherein each portwithin the set of ports is configured to receive data streams from anexternal medium, and to transmit data streams to an external medium; apath interconnection unit having an ingress side with a set of pathsequal to the number of ingress ports in the set of ports, and an egressside with a set of paths equal to the number of paths on the ingressside, and an electrical based switching fabric that is configured toswitch data streams on any one ingress side path to any one or moreegress side paths; and a control unit connected to the pathinterconnection unit configured to control the switching fabric toswitch data streams from a path on the ingress side to a path on theegress side.